Detection rules › Splunk

Windows Defender ASR or Threat Configuration Tamper

Status
production
Severity
medium
Group by
IntegrityLevel, command_line, computer_name, event_action, original_file_name, parent_command_line, parent_process_guid, parent_process_id, parent_process_name, process_guid, process_hash, process_id, process_name, user, user_id, vendor_product
Author
Nasreddine Bencherchali, Splunk
Source
github.com/splunk/security_content

The following analytic detects the use of commands to disable Attack Surface Reduction (ASR) rules or change threat default actions in Windows Defender. It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions involving "Add-MpPreference" or "Set-MpPreference". This activity is significant because adversaries often use it to bypass Windows Defender, allowing malicious code to execute undetected. If confirmed malicious, this behavior could enable attackers to evade antivirus detection, maintain persistence, and execute further malicious activities without interference from Windows Defender.

MITRE ATT&CK coverage

TacticTechniques
Defense ImpairmentT1685 Disable or Modify Tools

Event coverage

Rule body splunk

name: Windows Defender ASR or Threat Configuration Tamper
id: d0c07718-19d1-4de2-aea9-e0ffff0ed986
version: 6
creation_date: '2021-11-25'
modification_date: '2026-05-13'
author: Nasreddine Bencherchali, Splunk
status: production
type: TTP
description: |
    The following analytic detects the use of commands to disable Attack Surface Reduction (ASR) rules or change threat default actions in Windows Defender.
    It leverages data from Endpoint Detection and Response (EDR) agents, focusing on command-line executions involving "Add-MpPreference" or "Set-MpPreference".
    This activity is significant because adversaries often use it to bypass Windows Defender, allowing malicious code to execute undetected.
    If confirmed malicious, this behavior could enable attackers to evade antivirus detection, maintain persistence, and execute further malicious activities without interference from Windows Defender.
data_source:
    - Sysmon EventID 1
    - Windows Event Log Security 4688
    - CrowdStrike ProcessRollup2
search: |
    | tstats `security_content_summariesonly`
      count min(_time) as firstTime
            max(_time) as lastTime
    
    from datamodel=Endpoint.Processes where
    
    Processes.process IN ("*Add-MpPreference *", "*Set-MpPreference *")
    
    Processes.process IN (
          "*-AttackSurfaceReductionRules_Actions*",
          "*-ThreatIDDefaultAction_Actions*"
          )
    
    Processes.process IN (
          "*Allow*",
          "*NoAction*",
          "*Disabled*",
          "*_Actions 6*",
          "*_Actions 9*",
          "*_Actions 0*")
    
    by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
       Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
       Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec
       Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level
       Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product
    
    | `drop_dm_object_name(Processes)`
    | `security_content_ctime(firstTime)`
    | `security_content_ctime(lastTime)`
    | `windows_defender_asr_or_threat_configuration_tamper_filter`
how_to_implement: |
    The detection is based on data that originates from Endpoint Detection
    and Response (EDR) agents. These agents are designed to provide security-related
    telemetry from the endpoints where the agent is installed. To implement this search,
    you must ingest logs that contain the process GUID, process name, and parent process.
    Additionally, you must ingest complete command-line executions. These logs must
    be processed using the appropriate Splunk Technology Add-ons that are specific to
    the EDR product. The logs must also be mapped to the `Processes` node of the `Endpoint`
    data model. Use the Splunk Common Information Model (CIM) to normalize the field
    names and speed up the data modeling process.
known_false_positives: |
    Certain administrative tasks may require the modification of ASR rules or threat actions due to FPs being generated. Investigate all attempts and filter as needed.
references:
    - https://learn.microsoft.com/en-us/powershell/module/defender/set-mppreference?view=windowsserver2025-ps#-attacksurfacereductionrules-actions
    - https://www.virustotal.com/gui/file/7e805617c313ec2fb59d86719c827074cb7dfbf8f0aa18194ac1ffe6c21c8967/behavior
drilldown_searches:
    - name: View the detection results for - "$dest$" and "$user$"
      search: '%original_detection_search% | search  dest = "$dest$" user = "$user$"'
      earliest_offset: $info_min_time$
      latest_offset: $info_max_time$
    - name: View risk events for the last 7 days for - "$dest$" and "$user$"
      search: '| from datamodel Risk.All_Risk | search normalized_risk_object IN ("$dest$", "$user$") | stats count min(_time) as firstTime max(_time) as lastTime values(search_name) as "Search Name" values(risk_message) as "Risk Message" values(analyticstories) as "Analytic Stories" values(annotations._all) as "Annotations" values(annotations.mitre_attack.mitre_tactic) as "ATT&CK Tactics" by normalized_risk_object | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)`'
      earliest_offset: 7d
      latest_offset: "0"
finding:
    title: ASR or Threat detection tamper activity executed via $process$ on $dest$
    entity:
        field: user
        type: user
        score: 50
intermediate_findings:
    entities:
        - field: dest
          type: system
          score: 50
          message: ASR or Threat detection tamper activity executed via $process$ on $dest$
analytic_story:
    - Windows Defense Evasion Tactics
asset_type: Endpoint
mitre_attack_id:
    - T1685
product:
    - Splunk Enterprise
    - Splunk Enterprise Security
    - Splunk Cloud
category: endpoint
security_domain: endpoint
tests:
    - name: True Positive Test
      attack_data:
        - data: https://media.githubusercontent.com/media/splunk/attack_data/master/datasets/attack_techniques/T1562.001/disable_defender_asr_or_threats/disable_defender_asr_or_threats.log
          source: XmlWinEventLog:Microsoft-Windows-Sysmon/Operational
          sourcetype: XmlWinEventLog
      test_type: unit

Stages and Predicates

Stage 1: tstats

| tstats `security_content_summariesonly`
  count min(_time) as firstTime
        max(_time) as lastTime

from datamodel=Endpoint.Processes where

Processes.process IN ("*Add-MpPreference *", "*Set-MpPreference *")

Processes.process IN (
      "*-AttackSurfaceReductionRules_Actions*",
      "*-ThreatIDDefaultAction_Actions*"
      )

Processes.process IN (
      "*Allow*",
      "*NoAction*",
      "*Disabled*",
      "*_Actions 6*",
      "*_Actions 9*",
      "*_Actions 0*")

by Processes.action Processes.dest Processes.original_file_name Processes.parent_process
   Processes.parent_process_exec Processes.parent_process_guid Processes.parent_process_id
   Processes.parent_process_name Processes.parent_process_path Processes.process Processes.process_exec
   Processes.process_guid Processes.process_hash Processes.process_id Processes.process_integrity_level
   Processes.process_name Processes.process_path Processes.user Processes.user_id Processes.vendor_product

Stage 2: search

| `drop_dm_object_name(Processes)`

Stage 3: search

| `security_content_ctime(firstTime)`

Stage 4: search

| `security_content_ctime(lastTime)`

Stage 5: search

| `windows_defender_asr_or_threat_configuration_tamper_filter`

Indicators

Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.

FieldKindValues
Processes.processin
  • "*-AttackSurfaceReductionRules_Actions*"
  • "*-ThreatIDDefaultAction_Actions*"
  • "*Add-MpPreference *" corpus 4 (sigma 3, splunk 1)
  • "*Allow*" corpus 6 (sigma 4, splunk 2)
  • "*Disabled*" corpus 6 (sigma 5, splunk 1)
  • "*NoAction*"
  • "*Set-MpPreference *" corpus 4 (sigma 3, splunk 1)
  • "*_Actions 0*"
  • "*_Actions 6*"
  • "*_Actions 9*"